Impeovement in bit-beaces



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WILLIAM HENRY WOODS, or sA-N FRANCISCO, CALIFORNIA. Letters Patent No. 63,684, Jatefl April i), 1867.

IMPROVEMENT IN BIT-BRAGES.

TO A LL WHOM IT MAY CONCERN:

Be it known that I, WILLIAM HENRY Weens, of San Francisco city, San Francisco county, State of California, have invented a new and improved Bitl3race; and I dohereby declare the following description andl accompanying drawings are sufficient to enable any person skilled in the art or science to which it most nearly appertains to makeI and use mysaid invention without further invention or experiment.

The nature 'of my invention is to provide an improved bit-prece so constructed that the bit may bc easily and securely fastened to 'the stock, and the weer between the stationary and movable parts may be compensated for, and also much lessened. To accomplish these ends the brace has a. slot eut in `the side at the lower extremity, within which moves a key turning` on apivot at its upper end. A collar, the inside of which is eccentric, surrounds `the shaft of the brace and the key, and by simply turning it partly around forces the key into the depression ih the head 'of' the bit. At the upper end of the brace is an opening, inA which is pla-ced a small steel pin, which also fits loosely inthe head. Both-ends of this pin turn on a steel die, and anywcar is compensated by' a`cl1eck-nut`,'whieh can be inoved at pleasure ns necessity requires.

In order to more fu-ily expl-amthe work-ing cf inyinrention, reference is had -tc the accompanying drawing and letters mark-ed thereon, of whichT- Figure 1 is a side sectional elevation.

Figure 2 is an`end view of the lower end of the brace showing the cam.

Figure is `e. view of the collar.

Similar letters indica-te like-parts in each of the gures/.r 4

A is a. brace of my construction, having at its lower end, on one side, a slot, in which is placed the key a. This key turns on the pivot e, and has a projection, b, ut its lower extremity. B is a collar which surrounds the lower part of the brace, and is kept in place by the nut c. Its lower part is formed into the shape. of an cccentric-cam, as shown at d. By turning this collar the cam presses against the projection b, and forces' a similar one-on the inside `into the depression in the head of the bit.` The upperl end of the brace consists of the head C and the hollow cylinder or collar D, in `which is a cylindrical block, EE The head C is fastened to -E by the screw Fu A hole in the lower end of E receives la. small vsteel step, n z, onwhich turns one` end of the pin y Asimiiar step is placed in the body of the brace at n, supportingthe other end of the pin. G is n. check-nut, which is turned up against the collar D, so that allthe pressure and wear. may come on the pin g and the two steel steps. By moving this check-nut, when the pin is worn down, the other parts are saved from the friction, and nre so regulated that the wear comes ou the pin all the time. By using the eccentric-cam to Y tasten the hit in place this end is accomplished more thoroughly, and the slot lorgroovel in the end of the bit may be made very shallow. I i i A' i Having thus described my invention, wha-tl claim, 4and desire to secure by Letters Patent., is- The brace head, consisting of the'collar D, the block E, the pin g, and the steps m and n, with tle nut G, suhstantihlly as and for the purpose described. I i

In witness whereof I have hereunto set my hand and seal.

Witnesses C. W. M. Smrn, Gro. H. STRONG.

WILLIAM H. wo'oDs.. s.; 

